1. Field of the Invention
The present invention relates to a liquid crystal display, spacer particles for a liquid crystal display and a process for producing spacer particles, and particularly to a liquid crystal display and spacer particles for a liquid crystal display which can provide a homogeneous display by preventing an abnormal orientation of the liquid crystal around the spacers or between the spacers during energization.
2. Description of the Related Art
A liquid crystal display has a structure shown in FIG. 1. Specifically, a transparent electrode 3 patterned into a predetermined configuration and an orientation film 4 covering the transparent electrode 3 are provided on the surface of each of the upper and lower glass substrates 2, and a liquid crystal material 5 is provided in the space between the two glass substrates 2. The peripheral portions of the glass substrates 2 are sealed with a sealing agent 6. In order to maintain the liquid crystal cell gap constant, spacers 7 for the liquid crystal display are disposed in an evenly distributed manner. The liquid crystal cell gap is generally in the range of from 1 to 30 .mu.m. Finally, a polarizing plate 1 is provided on each of the outer sides of the glass substrates 2 to complete a liquid crystal display cell. With respect to the spacer 7, various polymer particles are known (see, for example, Japanese Patent Publication-A No. 246521/1991 (published on Nov. 1, 1991).
TN (twisted nematic) and STN (supertwisted nematic) liquid crystal panels have a problem in that an abnormal orientation of a liquid crystal occurs around the spacers or between the spacers in an energized state and this region, i.e., the region containing the abnormal orientation of the liquid crystal, increases with an increase in the energization time. Although the cause of the abnormal orientation has not yet been determined, the occurrence of the abnormal orientation is thought to be attributable to the interaction between the liquid crystal molecules and the surfaces of the liquid crystal spacers.
Further, static electricity tends to occur when a protective film is removed, which often brings about a problem in the occurrence of an abnormal orientation of the liquid crystal molecules around the spacers.
In order to prevent this unfavorable phenomenon, the so-called "aging operation (annealing step)" of the liquid crystal panel is conducted in the production of liquid crystal panels. This process, however, leads to problems such as a lowering in the production efficiency.